Cleansorb press release 29th August 2001

Press Release 29th August 2001

Excellent P/I for new well in sandstone formation following Arcasolve treatment

For Immediate Release:

Cleansorb is working with an operating company in Europe on using Arcasolve for clean up of water based carbonate/polymer mud in new wells drilled in a sandstone formation. An initial Arcasolve treatment on a new horizontal well with 1312 ft of 6.25 inch diameter producing open hole has been very successful.

The Arcasolve fluid was placed through the drill string and following shut in the well was gradually brought onto production. Bottom hole static and flowing pressure measurements made by the operator indicated a 0.15 bar drawdown with production running at 80 m3 of oil per day. The operator commented that the results "indicate at least 10 times higher productivity than productivity of vertical wells at the same field".

The data for this well indicate a P/I of 223 (b/d/psi) which compares favourably with horizontal wells reported in SPE 68943 "How Good Are Your Horizontal Wells" presented at the SPE European Formation Damage conference in Den Hague in May 2001.

For further information please contact:

Dr Ian McKay or Dr Ralph Harris

Cleansorb Ltd, Surrey Technology Centre , 40 Occam Road, Surrey Research Park, Guildford, Surrey GU2 7YG, U.K.

Tel. ++44 (0)1483 295090

Fax. ++44 (0)1483 845358

email:

Notes for editors:

1. Arcasolve^TM has been developed by Cleansorb Limited, based at the Surrey Research Park in Guildford, Surrey, UK. The process combines enzymes (biological catalysts) with suitable chemicals to generate organic acid at a controlled rate in the fluid injected into the wellbore or formation. The bulk of the acid is produced after placement of the fluid, permitting the efficient and even delivery of acid to the target zones maximizing the production rate of the well and its value to the operator. Arcasolve^TM is environmentally friendly and very low hazard. Conventional acids are hazardous in use and generally require the use of toxic corrosion inhibitors.

2. A catalyst is a compound which promotes a chemical reaction without itself being consumed. The catalyst used in the Arcasolve^TM process is an enzyme. Enzymes are chemical compounds found in nature. They are however single chemical compounds which can be manufactured to the usual standards of purity of industrial chemicals.

3. Although Arcasolve ^TMis a biotechnological process it should be clearly distinguished from previous stimulation processes based on bacteria. Using enzymes confers many advantages including a high level of process control, high yield and better thermotolerance. Enzyme based systems are also particulate free.

4. Arcasolve^TM has been granted Millennium Products status by the UK Design Council. This means that it has been independently recognized as an innovative product which will change working practices in the 21st century.

5. Cleansorb Limited, based at the Surrey Research Park, Guildford, Surrey, UK, is a privately owned biotechnology company which specializes in developing enzyme-based processes which assist oil and gas production. Contact: Ian McKay or Ralph Harris, Tel. ++44 (0) 1483 295090

Fax. ++44 (0) 1483 845358.

6. In addition to Arcasolve^TM, Cleansorb has other award winning enzyme-based processes under development which allow the controlled deposition of gels, minerals or resins in underground reservoirs. These have a number of applications in oil and gas production.